As davej was alluding to, we've started trying to make progress on a new initramfs infrastructure that can be used across distributions instead of just being done for a single distribution. Thus far, the code is fairly early and proof-of-concept-y, but I can successfully boot root partitions, root on LVM or root on encrypted LVM. The next step is to clean up the build side so that I can switch to using it with my laptop. I wanted to go ahead and get the code out first, though.
The majority of the ideas behind the code are that we want to use the same tools and utilities that exist on the booted system (so regular bash, regular udev, no nash, no statically linked nonsense, no klibc) and also that we want to not have the initramfs as a slow-down. The latter means that we run pretty much everything off of udev rules right now so that as soon as the devices are available, we mount and switch into the rootfs.
So go ahead 'git clone git://fedorapeople.org/~katzj/dracut.git' and read the README, HACKING and TODO files. Also sent to lkml to get the mailing list started. More hands more than welcome…